NeoNet Atlantic dataset complements the NeoNet Mediterranean dataset by providing new curated radiocarbon dates for the study of the pioneer farming front (i.e. Neolithisation, ca. 7500 to 3500 cal BC) in the Southern European Atlantic Coast river basin (Portugal, Western Spain, Southwestern France). The complete dataset is formed by the id00164_doc_elencoc14.tsv file, a data frame with tab-separated values, and a related dataframe: id00164_doc_thesaurus.tsv. The dataset contains 1,143 radiocarbon dates from 254 archaeological sites and 817 different archaeological contexts (stratigraphic units, structures, negative features, hearths, etc.) informed by 233 bibliographical references. As for the NeoNet Mediterranean dataset, particular attention has been paid to homogenisation of the laboratory code, the archaeological context, and the references, in order to facilitate further data extractions. Indeed, the dataset is linked to an open source R Shiny interactive web app (NeoNet app), a series of functions hosted on GitHub, and a getter function (R package c14bazAAr, R function get_c14data("neonetatl").